CVE-2026-100071

net: hsr: free learned nodes on device setup failure

MEDIUM
5.5
CVSS Score
Published: September 25, 2026 at 01:06 PM UTC
Updated: October 21, 2026 at 06:46 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

Description

In the Linux kernel, the following vulnerability has been resolved: net: hsr: free learned nodes on device setup failure hsr_dev_finalize() can fail after a lower-device RX handler has already been registered (slave A is added before the failable slave B and interlink adds). RX handlers run in softirq regardless of the master's state, so frames received in that window can learn dynamic nodes into node_db, and the error unwind never releases them. Free both owned dynamic databases in the unwind, mirroring hsr_dellink(). proxy_node_db is provably empty on every current error exit (only interlink RX feeds it, and the interlink add is the last failable step) and is freed for symmetry. The order is safe: hsr_del_port() unregisters each RX handler with synchronize_net() before hsr_del_nodes() runs, which removes remaining entries with list_del_rcu() and defers their release with call_rcu() for readers already under RCU.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

3.17 ≤ v < 6.1.1886.13 ≤ v < 6.18.526.19 ≤ v < 7.2.66.2 ≤ v < 6.6.1576.7 ≤ v < 6.12.1103.1781ba6afd6e6443d2bf4bf40f16df1f1f91c603f8
Vendor states this is fixed in 0a340ffd96943a49a78e367efac9517ca767d99b (fixed)
Vendor states this is fixed in 49b01f2939abc676a6f9a118f07a10110ee5f683 (fixed)
Vendor states this is fixed in 65702339b3e9fd792f65d4b740928798194d86ce (fixed)
Vendor states this is fixed in 7f16289b91eb316f170a6bd22d32e6c632f6a5b6 (fixed)
Vendor states this is fixed in e691eee886871b933d772ffc76d66c80b4c0a25e (fixed)
Vendor states this is fixed in f7289e3492f2694dccd3d79287e0e31879b58650 (fixed)
Vendor states this is fixed in 3.17 (unaffected)
Vendor states this is fixed in 6.1.188 (unaffected)
Vendor states this is fixed in 6.12.110 (unaffected)
Vendor states this is fixed in 6.18.52 (unaffected)
Vendor states this is fixed in 6.6.157 (unaffected)
Vendor states this is fixed in 7.2.6 (unaffected)
Vendor states this is fixed in 7.3 (unaffected)
Vendor states this is fixed in 7.3-rc1 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
NVD-CWE-noinfo

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